Uplink grant management for lte in unlicensed spectrum

ABSTRACT

Systems and methods for uplink transmission scheduling are disclosed. A wireless device may monitor at least two downlink sub-frames for scheduling grants. The wireless device may receive a first uplink scheduling grant in one of the at least two downlink sub-frames for at least a first uplink sub-frame and receive a second uplink scheduling grant in another of the at least two downlink sub-frames for at least the first uplink sub-frame. The wireless device may perform an uplink transmission in the first uplink sub-frame based on one or both of the first uplink scheduling grant and the second uplink scheduling grant. For the uplink transmission, the wireless device may select a most recent uplink scheduling grant or select an uplink scheduling grant received in a downlink sub-frame at least a minimum number of sub-frames before the first uplink sub-frame.

CROSS-REFERENCE TO RELATED CASES

The present Application for Patent is a continuation of U.S. applicationSer. No. 14/869,779, entitled “UPLINK GRANT MANAGEMENT FOR LTE INUNLICENSED SPECTRUM,” filed Sep. 29, 2015, which claims priority to U.S.Provisional Application No. 62/057,954, entitled “UPLINK GRANTMANAGEMENT FOR LTE IN UNLICENSED SPECTRUM” filed Sep. 30, 2014, both ofwhich are assigned to the assignee hereof and hereby expresslyincorporated by reference herein.

BACKGROUND

Aspects of this disclosure relate generally to telecommunications, andmore particularly to uplink scheduling.

Wireless communication networks are widely deployed to provide variouscommunication services such as voice, video, packet data, messaging,broadcast, etc. These wireless networks may be multiple-access networkscapable of supporting multiple users by sharing the available networkresources. Examples of such multiple-access networks include CodeDivision Multiple Access (CDMA) networks, Time Division Multiple Access(TDMA) networks, Frequency Division Multiple Access (FDMA) networks,Orthogonal FDMA (OFDMA) networks, and Single-Carrier FDMA (SC-FDMA)networks.

A long-term evolution (LTE) wireless communication network may include anumber of eNodeBs that can support communication for a number of userequipments (UEs). A UE may communicate with an eNodeB via the downlinkand uplink. The downlink (or forward link) refers to the communicationlink from the eNodeB to the UE, and the uplink (or reverse link) refersto the communication link from the UE to the eNodeB.

Operation of wireless devices in certain portions of a shared orunlicensed spectrum may experience interference from another radioaccess technology (RAT) using the spectrum. For example, both LTE andWi-Fi may operate in an unlicensed 5 GHz band. Over-the-air interferencedetection is employed in some wireless communication networks in anattempt to mitigate such interference. For example, a device mayperiodically monitor (e.g., sniff) for energy in the RF band used by thedevice. Upon detection of any kind of energy, the device may back-offthe RF band for a period of time. Such process may be referred to asclear channel assessment (CCA).

In practice, however, there may be problems with such a back-off or“listen-before-talk” (LBT) approach, at least when applied to radiotechnologies using a frame structure and uplink grants. For example, foran LTE system operating in an unlicensed or shared band, a UE may needto consider both uplink grants scheduled by the eNodeB and LBT or CCArequirements. In view of the foregoing, it may be understood that theremay be significant problems and shortcomings associated with operationof wireless devices in shared and unlicensed spectrum.

SUMMARY

Various aspects are now described with reference to the drawings. In thefollowing description, for purposes of explanation, numerous specificdetails are set forth in order to provide a thorough understanding ofone or more aspects. It may be evident, however, that such aspects maybe practiced without these specific details. The following presents asimplified summary of one or more aspects in order to provide a basicunderstanding of such aspects.

Systems and methods for uplink transmission scheduling are disclosed. Awireless device may monitor at least two downlink sub-frames forscheduling grants. The wireless device may receive a first uplinkscheduling grant in one of the at least two downlink sub-frames for atleast a first uplink sub-frame and receive a second uplink schedulinggrant in another of the at least two downlink sub-frames for at leastthe first uplink sub-frame. The wireless device may select one or bothof the first uplink scheduling grant and the second uplink schedulinggrant for an uplink transmission in the first uplink sub-frame. A basestation may transmit a first uplink scheduling grant for at least afirst uplink sub-frame and a second uplink scheduling grant for at leastthe first uplink sub-frame. The base station may receive, in the firstuplink sub-frame, an uplink transmission. The base station may processthe uplink transmission according to at least one of the first uplinkscheduling grant or the second uplink scheduling grant.

In an aspect, the disclosure provides method for transmitting scheduleduplink wireless transmissions. The method may include monitoring atleast two downlink sub-frames for scheduling grants. The method mayfurther include receiving a first uplink scheduling grant in one of theat least two downlink sub-frames for at least a first uplink sub-frameand receiving a second uplink scheduling grant in another of the atleast two downlink sub-frames for at least the first uplink sub-frame.The method may also include performing an uplink transmission in thefirst uplink sub-frame based on one or both of the first uplinkscheduling grant and the second uplink scheduling grant.

In another aspect, the disclosure provides an apparatus for transmittingscheduled uplink wireless transmissions. The apparatus may include meansfor monitoring at least two downlink sub-frames for scheduling grants.The apparatus may further include means for receiving a first uplinkscheduling grant in one of the at least two downlink sub-frames for atleast a first uplink sub-frame and means for receiving a second uplinkscheduling grant in one of the at least two downlink sub-frames for atleast the first uplink sub-frame. The apparatus may also include meansfor performing an uplink transmission in the first uplink sub-framebased on one or both of the first uplink scheduling grant and the seconduplink scheduling grant.

In another aspect, the disclosure provides another apparatus fortransmitting scheduled uplink wireless transmissions. The apparatus mayinclude a transceiver configured to receive scheduling grants in one ormore downlink sub-frames and transmit data in one or more uplinksub-frames. The apparatus may further include a memory and a processorcommunicatively coupled to the transceiver and the memory. The processorand the memory may be configured to monitor, via the transceiver, atleast two of the one or more downlink sub-frames for the schedulinggrants. The processor and the memory may also be configured to receive afirst uplink scheduling grant in one of the at least two downlinksub-frames for at least a first uplink sub-frame of the one or moreuplink sub-frames. The processor and the memory may additionally beconfigured to receive a second uplink scheduling grant in another of theat least two downlink sub-frames for at least the first uplinksub-frame. The processor and the memory may further be configured toperform an uplink transmission in the first uplink sub-frame based onone or both of the first uplink scheduling grant and the second uplinkscheduling grant.

In another aspect, the disclosure provides a computer-readable mediumstoring computer executable code for transmitting scheduled uplinkwireless transmissions. The computer-readable medium may include codefor monitoring at least two downlink sub-frames for scheduling grants.The computer-readable medium may further include code for receiving afirst uplink scheduling grant in one of the at least two downlinksub-frames for at least a first uplink sub-frame. The computer-readablemedium may also include code for receiving a second uplink schedulinggrant in another of the at least two downlink sub-frames for at leastthe first uplink sub-frame. The computer-readable medium may alsoinclude code for performing an uplink transmission in the first uplinksub-frame based on one or both of the first uplink scheduling grant andthe second uplink scheduling grant. The computer readable medium may bea non-transitory computer readable medium.

In another aspect, the disclosure provides a method for schedulinguplink wireless transmissions. The method may include transmitting, to adevice, a first uplink scheduling grant for at least a first uplinksub-frame and transmitting, to the device, a second uplink schedulinggrant for at least the first uplink sub-frame. The method may furtherinclude receiving, in the first uplink sub-frame, an uplink transmissionfrom the device. The method may also include processing the uplinktransmission according to one of the first uplink scheduling grant andthe second uplink scheduling grant.

In another aspect, the disclosure provides an apparatus for schedulinguplink wireless transmissions. The apparatus may include means fortransmitting, to a device, a first uplink scheduling grant for at leasta first uplink sub-frame and means for transmitting, to the device, asecond uplink scheduling grant for at least the first uplink sub-frame.The apparatus may also include means for receiving, in the first uplinksub-frame, an uplink transmission from the device. The apparatus mayfurther include means for processing the uplink transmission accordingto one of the first uplink scheduling grant and the second uplinkscheduling grant.

In another aspect, the disclosure provides another apparatus forscheduling uplink wireless transmissions. The apparatus may include atransmitting component configured to transmit, to a device, a firstuplink scheduling grant for at least a first uplink sub-frame, andtransmit to the device, a second uplink scheduling grant for at leastthe first uplink sub-frame. The apparatus may also include a receivingcomponent configured to receive, in the first uplink sub-frame, anuplink transmission from the device. The apparatus may further include adecoding component configured to process the uplink transmissionaccording to one of the first uplink scheduling grant and the seconduplink scheduling grant.

In another aspect, the disclosure provides a computer-readable mediumstoring computer executable instructions for scheduling uplink wirelesstransmissions. The computer-readable medium may include code fortransmitting, to a device, a first uplink scheduling grant for at leasta first uplink sub-frame and code for transmitting, to the device, asecond uplink scheduling grant for at least the first uplink sub-frame.The computer-readable medium may further include code for receiving, inthe first uplink sub-frame, an uplink transmission from the device. Thecomputer-readable medium may also include code for processing the uplinktransmission according to one of the first uplink scheduling grant andthe second uplink scheduling grant. The computer readable medium may bea non-transitory computer readable medium.

In another aspect, the disclosure provides a method for performingwireless transmissions. The method may include identifying a framestructure, where the frame structure comprises at least two or moresub-frames for a same transmission direction. The method may alsoinclude performing a first clear channel assessment before transmittingin a first set of sub-frames of the at least two or more sub-frames. Themethod may further include transmitting in the first set of sub-framesbased on the first clear channel assessment. The method may also includedetermining whether to perform a second clear channel assessment beforetransmitting in a second set of sub-frames of the at least two or moresub-frames, where the second set of sub-frames are after the first setof sub-frames in the frame. The method may also include transmitting inthe second set of sub-frames based on the second channel assessment.Additionally, the disclosure provides an apparatus for performing themethod and a computer-readable medium storing executable code forperforming the method.

Various aspects and features of the disclosure are described in furtherdetail below with reference to various examples thereof as shown in theaccompanying drawings. While the present disclosure is described belowwith reference to various examples, it should be understood that thepresent disclosure is not limited thereto. Those of ordinary skill inthe art having access to the teachings herein will recognize additionalimplementations, modifications, and examples, as well as other fields ofuse, which are within the scope of the present disclosure as describedherein, and with respect to which the present disclosure may be ofsignificant utility.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are presented to aid in the description ofvarious aspects of the disclosure and are provided solely forillustration of the aspects and not limitation thereof.

FIG. 1 is a simplified block diagram of several sample aspects of acommunication system.

FIG. 2 illustrates an example frame structure for time divisionduplexing.

FIG. 3 is a block diagram conceptually illustrating example transmissionscheduling.

FIG. 4 is a block diagram conceptually illustrating a frameconfiguration with one downlink sub-frame.

FIG. 5 is a block diagram conceptually illustrating a frameconfiguration with two downlink sub-frames.

FIG. 6 is a flow diagram illustrating an example method of uplinktransmission.

FIG. 7 is a flow diagram illustrating an example method of transmittingscheduled uplink wireless transmissions.

FIG. 8 is a flow diagram illustrating an example method of uplinktransmission scheduling.

FIG. 9 is a simplified block diagram of several sample aspects ofcomponents that may be employed in communication nodes.

FIG. 10 is a simplified block diagram of several sample aspects ofcommunication components.

DETAILED DESCRIPTION

The disclosure relates in some aspects to scheduling uplinktransmissions using grants, in particular, in unlicensed spectrum. Acommunications system may use time division duplexing (TDD) to allowboth downlink and uplink transmissions over the same portion of spectrum(e.g., channel, carrier, or frequency band). For example, transmissionson a carrier may be organized in a frame structure. For example, an LTEframe structure may be used, and the terms radio frame, LTE frame, andframe may be used interchangeably. In an aspect, a frame having a TDDframe structure may include downlink sub-frames, uplink sub-frames, andspecial sub-frames. The eNodeB may transmit a scheduling grant to a UEduring a downlink sub-frame. The scheduling grant may assign resourceelements (RE) a modulation and coding scheme (MCS), and/or a waveform,to the UE to use for an uplink transmission during one or moresub-frames. In an aspect, a scheduling system for LTE in unlicensedspectrum may need to balance signaling overhead and flexibility forchanging conditions.

In an aspect, the eNodeB may transmit one or more additional schedulinggrants during subsequent downlink sub-frames for one or more uplinksub-frames. Further, in some aspects, a second eNodeB, such as asecondary eNodeB operating on a second carrier, may also provideadditional uplink scheduling grants. Accordingly, the UE may receive twoor more scheduling grants for the same uplink sub-frame. In an aspect,the UE may select one of the uplink scheduling grants for an uplinktransmission during the uplink sub-frame. For example, but not limitedhereto, the UE may select the most recently received uplink schedulinggrant. The UE may also include an indication of the selected schedulinggrant in an uplink transmission.

Aspects of the disclosure are provided in the following description andrelated drawings directed to specific disclosed aspects. Alternateaspects may be devised without departing from the scope of thedisclosure. Additionally, well-known aspects of the disclosure may notbe described in detail or may be omitted so as not to obscure morerelevant details. Further, many aspects are described in terms ofsequences of actions to be performed by, for example, elements of acomputing device. It will be recognized that various actions describedherein can be performed by specific circuits (e.g., application specificintegrated circuits (ASICs)), by program instructions being executed byone or more processors, or by a combination of both. Additionally, thesesequence of actions described herein can be considered to be embodiedentirely within any form of computer readable storage medium havingstored therein a corresponding set of computer instructions that uponexecution would cause an associated processor to perform thefunctionality described herein. Thus, the various aspects of thedisclosure may be embodied in a number of different forms, all of whichhave been contemplated to be within the scope of the claimed subjectmatter. In addition, for each of the aspects described herein, thecorresponding form of any such aspects may be described herein as, forexample, “logic configured to” perform the described action.

FIG. 1 illustrates several nodes of a sample communication system 100(e.g., a portion of a communication network). For illustration purposes,various aspects of the disclosure will be described in the context ofone or more user equipment (UE) 110 and evolved NodeB (eNodeB) 160. Theuser equipment (UE) 110 may be in communication with the eNodeB 160. TheeNode B 160 may schedule uplink transmissions 152 for the UE 110. Forexample, the eNodeB 160 may transmit uplink scheduling grants 150indicating at least resources and a modulation and coding scheme for theUE 110 to use for an uplink transmission in an uplink sub-frame. In anaspect, the term “grant” and “uplink scheduling grant” may be usedinterchangeably to refer to an uplink scheduling grant 150. Further, theterm “received grant” may be used to refer to an uplink scheduling grant150 that has been received by a UE 110. It should be appreciated,however, that the teachings herein may be applicable to other types ofapparatuses or other similar apparatuses that are referenced using otherterminology. For example, in various implementations, eNodeBs 160 may bereferred to or implemented as access points, base stations, NodeBs, HomeNodeBs, Home eNodeBs, small cells, macro cells, femto cells, and so on,while UEs 110 may be referred to or implemented as access terminals,mobile stations, and so on.

For convenience, the use, operation, extension, and/or adaptation of LTEand/or LTE Advanced for applications in an unlicensed or shared radiofrequency (RF) band may be referred to herein as “LTE/LTE Advanced inunlicensed spectrum,” “adapting LTE/LTE Advanced in unlicensedspectrum,” “extending LTE/LTE Advanced to unlicensed spectrum,” and“LTE/LTE Advanced communications over unlicensed spectrum” etc.Moreover, a network or device that provides, adapts, or extends LTE/LTEAdvanced in unlicensed spectrum may refer to a network or device that isconfigured to operate in a contention-based radio frequency band orspectrum.

In some systems, LTE in unlicensed spectrum may be employed in astandalone configuration, with all carriers operating exclusively in anunlicensed portion of the wireless spectrum (e.g., LTE Standalone). Inother systems, LTE in unlicensed spectrum may be employed in a mannerthat is supplemental to licensed band operation by providing one or moreunlicensed carriers operating in the unlicensed portion of the wirelessspectrum in conjunction with an anchor licensed carrier operating in thelicensed portion of the wireless spectrum (e.g., LTE Supplemental DownLink (SDL)). In either case, carrier aggregation may be employed tomanage the different component carriers, with one carrier serving as thePrimary Cell (PCell) for the corresponding UE (e.g., an anchor licensedcarrier in LTE SDL or a designated one of the unlicensed carriers in LTEStandalone) and the remaining carriers serving as respective SecondaryCells (SCells). In this way, the PCell may provide an FDD paireddownlink and uplink (licensed or unlicensed) or TDD downlink and uplink,and each SCell may provide additional downlink capacity as desired.

In general, LTE utilizes orthogonal frequency division multiplexing(OFDM) on the downlink and single-carrier frequency divisionmultiplexing (SC-FDM) on the uplink. In an aspect, either OFDM or SC-FDMmay be utilized on the uplink on a per sub-frame basis. OFDM and SC-FDMpartition the system bandwidth into multiple (K) orthogonal subcarriers,which are also commonly referred to as tones, bins, etc. Each subcarriermay be modulated with data. In general, modulation symbols are sent inthe frequency domain with OFDM and in the time domain with SC-FDM. Thespacing between adjacent subcarriers may be fixed, and the total numberof subcarriers (K) may be dependent on the system bandwidth. Forexample, K may be equal to 128, 256, 512, 1024 or 2048 for systembandwidth of 1.25, 2.5, 5, 10 or 20 megahertz (MHz), respectively. Thesystem bandwidth may also be partitioned into sub-bands. For example, asub-band may cover 1.08 MHz, and there may be 1, 2, 4, 8 or 16 sub-bandsfor system bandwidth of 1.25, 2.5, 5, 10 or 20 MHz, respectively.

LTE may also use carrier aggregation. UEs (e.g., LTE-Advanced enabledUEs) may use spectrum of up to 20 MHz bandwidths allocated in a carrieraggregation of up to a total of 100 MHz (5 component carriers) used fortransmission and reception. For the LTE-Advanced enabled wirelesscommunication systems, two types of carrier aggregation (CA) methodshave been proposed, continuous CA and non-continuous CA. Continuous CAoccurs when multiple available component carriers are adjacent to eachother. On the other hand, non-continuous CA occurs when multiplenon-adjacent available component carriers are separated along thefrequency band. Both non-continuous and continuous CA may aggregatemultiple component carriers to serve a single unit of LTE-Advanced UEs.

According to the present aspects, the UE 110 may include one or moreprocessors 103 that may operate in combination with an uplink scheduler120 for managing uplink transmissions based on scheduling grantsreceived by the UE 110. The uplink scheduler 120 may include hardware,firmware, and/or software code executable by a processor 103 forscheduling an uplink transmission during a time slot (e.g., an uplinksub-frame) based on multiple scheduling grants, the code comprisinginstructions and being stored in a memory (e.g., computer-readablemedium). The uplink scheduler 120 may include a downlink monitoringcomponent 122 for monitoring at least two downlink sub-frames forscheduling grants, a grant receiving component 124 for receiving atleast two uplink scheduling grants in the at least two downlinksub-frames for at least a first uplink sub-frame, a grant selectingcomponent 126 for selecting one of the uplink scheduling grants for anuplink transmission in the first uplink sub-frame, and a transmittingcomponent 128 for transmitting the uplink transmission. In an aspect,the term “component” as used herein may be one of the parts that make upa system, may be hardware or software, and may be divided into othercomponents.

The receiver 32 may include hardware, firmware, and/or software codeexecutable by a processor (e.g. a processor of transceiver 106) forreceiving data, the code comprising instructions and being stored in amemory (e.g., computer-readable medium). The receiver 32 may be, forexample, a radio frequency (RF) receiver. In an aspect, the receiver 32may receive signals transmitted by the eNodeB 160. The receiver 32 mayobtain measurements of the signals. For example, the receiver 32 maydetermine Ec/Io, SN_(R), etc.

The transmitter 34 may include hardware, firmware, and/or software codeexecutable by a processor (e.g. a processor of transceiver 106) fortransmitting data, the code comprising instructions and being stored ina memory (e.g., computer-readable medium). The transmitter 34 may be,for example, a RF transmitter.

In an aspect, the one or more processors 103 can include one or moremodem processors that provide a modem 108. The various functions relatedto uplink scheduling and transmission may be included in modem 108and/or processors 103 and, in an aspect, can be executed by a singleprocessor, while in other aspects, different ones of the functions maybe executed by a combination of two or more different processors. Forexample, in an aspect, the one or more processors 103 may include anyone or any combination of a modem processor, or a baseband processor, ora digital signal processor, or a transmit processor, or a transceiverprocessor associated with transceiver 106. In particular, the one ormore processors 103 may implement components included in uplinkscheduler 120, including the downlink monitoring component 122 formonitoring at least two downlink sub-frames for scheduling grants, agrant receiving component 124 for receiving at least two uplinkscheduling grants for at least a first uplink sub-frame, a grantselecting component 126 for selecting one of the uplink schedulinggrants for an uplink transmission in the first uplink sub-frame, and atransmitting component 128 for transmitting the uplink transmission.

The downlink monitoring component 122 may include hardware, firmware,and/or software code executable by a processor (e.g., processor(s) 103)for monitoring one or more downlink sub-frames for uplink schedulinggrants 150, the code comprising instructions and being stored in amemory (e.g., memory 105 or another computer-readable medium). Forexample, the downlink monitoring component 122 may include or control anantenna 102, RF front end 104, and/or receiver 32. The downlinkmonitoring component 122 may be configured to monitor a set of downlinksub-frames in one or more frames that may carry a grant 150. In anaspect, downlink sub-frames that may carry a grant 150 may be determinedbased on a frame structure or uplink-downlink configuration. In anaspect, a frame structure may define properties of the frame including alength of the frame, a number of sub-frames, and a length of sub-frames.An uplink-downlink configuration may indicate which of the sub-frames inthe frame is designated as an uplink sub-frame (U), a downlink sub-frame(D), or a special sub-frame (S′). For example, the frame structure mayindicate that there are multiple downlink sub-frames in a frame and thatthe first downlink sub-frame and the last downlink sub-frame of theframe may be designated for carrying grants 150. The downlink monitoringcomponent 122 may monitor multiple frames to identify the appropriatedownlink sub-frames. In another aspect, a special sub-frame may carry agrant 150. For example, a downlink pilot time slot (DwPTS) portion ofthe special sub-frame may carry a grant 150. The downlink monitoringcomponent 122 may receive signals, which may include the uplinkscheduling grants 150 during the designated downlink sub-frames forcarrying the grants 150. The downlink monitoring component 122 may powerdown during other sub-frames not designated for carrying a grant 150 ifno downlink traffic is scheduled for the UE 110.

The grant receiving component 124 may include hardware, firmware, and/orsoftware code executable by a processor (e.g., processor(s) 103) forreceiving uplink scheduling grants in the downlink sub-frames, the codecomprising instructions and being stored in a memory (e.g., memory 105or another computer-readable medium). For example, the grant receivingcomponent 124 may include or control the receiver 32 to decode a grant150. The grant receiving component 124 may determine a format of thegrant 150. In an aspect, the grant receiving component 124 may determinethe format of the grant 150 based on a frame structure. For example, thegrant receiving component 124 may determine the length of the grant 150or the resource elements carrying the uplink scheduling grant 150 basedon the frame structure. The grant receiving component 124 may decode thereceived uplink scheduling grant 150 according to the determined format.The grant receiving component 124 may extract information elements fromthe uplink scheduling grant 150 such as uplink sub-frame numbers, HARQprocess identifiers, modulation and coding schemes, waveforms, or anyother information the uplink scheduling grant provides for an uplinktransmission. The grant receiving component 124 may receive multipleuplink scheduling grants for a single uplink sub-frame.

The grant selecting component 126 may include hardware, firmware, and/orsoftware code executable by a processor (e.g., processor(s) 103) forselecting an uplink scheduling grant to use for an uplink transmissionduring an uplink sub-frame, the code comprising instructions and beingstored in a memory (e.g., memory 105 or another computer-readablemedium). If only one grant 150 is received, the grant selectingcomponent 126 may select the one available grant. If multiple uplinkscheduling grants are received, the grant selecting component 126 mayselect one or more uplink scheduling grants according to configuredpriority rules. For example, a priority rule may indicate that the mostrecently received grant 150 should be used. Further priority rules mayindicate a minimum time (e.g., 4 sub-frames) between receipt of anuplink scheduling grant 150 and an uplink sub-frame. In another aspect,the priority rules may configure the grant selecting component 126 toselect an uplink scheduling grant 150 allowing a minimum size or amaximum size for a transmission. Examples of priority rules aredescribed in further detail below regarding FIGS. 2-5. In an aspect, ifthe grant selecting component 126 determines that more than one grant isapplicable, the grant selecting component 126 may combine the grants150. For example, the grant selecting component 126 may combine powercontrol commands from two or more grants. The grant selecting component126 may also combine resource allocations from two or more grants. Forexample, the grant selecting component 126 may determine that the UE 110may transmit on all of the resources indicated in both a first grant anda second grant.

The transmitting component 128 may include hardware, firmware, and/orsoftware code executable by a processor (e.g., processor(s) 103) forperforming an uplink transmission in the first uplink sub-frame based onone or both of the first uplink scheduling grant and the second uplinkscheduling grant, the code comprising instructions and being stored in amemory (e.g., memory 105 or another computer-readable medium). Forexample, the transmitting component 128 may include or control atransmitter 34 for performing the uplink transmission 152. Thetransmitting component 128 may determine data to transmit based on oneor both of the first uplink scheduling grant and the second uplinkscheduling grant selected for the uplink transmission. The transmittingcomponent 128 may use the resources assigned by the one or more selectedgrants to modulate an RF carrier to transmit the data. In an aspect, thetransmitting component 128 may be configured to provide signalingrelated to the uplink transmission. For example, the transmittingcomponent 128 may provide an indication of one or more uplink schedulinggrants used for the transmission. For example, the indication may be abit flag indicating whether the selected grant is a first received grantor a second received grant. As another example, a bit-map may be used toindicate whether each received grant was used for the uplinktransmission.

The channel assessing component 129 may include hardware, firmware,and/or software code executable by a processor (e.g., processor(s) 103)configured to determine whether a channel is available for atransmission, the code comprising instructions and being stored in amemory (e.g., memory 105 or another computer-readable medium). Forexample, channel assessing component 129 may include or control areceiver 32 to measure received signal energy in a channel. Channelassessing component 129 may determine that a channel or medium is clearwhen the signal energy falls below a threshold value. In an aspect,channel assessing component 129 may determine whether a channel isavailable according to regulations or a standard. For example, EN301.893 may define LBT procedures. IEEE 802.11 and 802.15 standards maydefine clear channel assessment (CCA) procedures. Generally, the CCAprocedures may involve monitoring a channel for a CCA duration or timeslot, for example 20 microseconds (μs). If the channel is clear duringthe time slot (e.g., the communications medium is available oraccessible), the device may begin using or accessing the channel. If thechannel is not clear, the device may determine a random backoff counterfor the channel. Each time the device detects a clear time slot, therandom backoff counter is decremented. In an aspect, the UE 110 mayperform CCA or an extended CCA (ECCA) prior to an uplink transmission todetermine that the channel or medium is clear for the uplinktransmission. The channel assessing component 129 may perform a CCAprocedure prior to a first uplink sub-frame (e.g. during a specialsub-frame). The UE 110 may continue to transmit in subsequentsub-frames. If the UE 110 is not scheduled to transmit in a sub-frame,the channel assessing component 129 may perform CCA again before thenext scheduled uplink sub-frame.

Moreover, in an aspect, UE 110 may include RF front end 104 andtransceiver 106 for receiving and transmitting radio transmissions, forexample, grant 150 transmitted by the eNodeB 160. For example,transceiver 106 may receive a signal that includes a physical downlinkcontrol channel (PDCCH) from the eNodeB 160. The transceiver 106 maydemodulate the received signal to obtain the grant 150, which may thenbe considered a received grant. Further, the transceiver 106 maytransmit the uplink transmission 152.

RF front end 104 may be connected to one or more antennas 102 and caninclude one or more low-noise amplifiers (LNAs) 141, one or moreswitches 142, 143, one or more power amplifiers (PAs) 145, and one ormore filters 144 for transmitting and receiving RF signals. In anaspect, components of RF front end 104 can connect with transceiver 106.Transceiver 106 may connect to one or more modems 108 and processor 103.

In an aspect, LNA 141 can amplify a received signal at a desired outputlevel. In an aspect, each LNA 141 may have a specified minimum andmaximum gain values. In an aspect, RF front end 104 may use one or moreswitches 142, 143 to select a particular LNA 141 and its specified gainvalue based on a desired gain value for a particular application.

Further, for example, one or more PA(s) 145 may be used by RF front end104 to amplify a signal for an RF output at a desired output powerlevel. In an aspect, each PA 145 may have a specified minimum andmaximum gain values. In an aspect, RF front end 104 may use one or moreswitches 143, 146 to select a particular PA 145 and its specified gainvalue based on a desired gain value for a particular application.

Also, for example, one or more filters 144 can be used by RF front end104 to filter a received signal to obtain an input RF signal. Similarly,in an aspect, for example, a respective filter 144 can be used to filteran output from a respective PA 145 to produce an output signal fortransmission. In an aspect, each filter 144 can be connected to aspecific LNA 141 and/or PA 145. In an aspect, RF front end 104 can useone or more switches 142, 143, 146 to select a transmit or receive pathusing a specified filter 144, LNA, 141, and/or PA 145, based on aconfiguration as specified by transceiver 106 and/or processor 103.

Transceiver 106 may be configured to transmit and receive wirelesssignals through antenna 102 via RF front end 104. In an aspect,transceiver may be tuned to operate at specified frequencies such thatUE 110 can communicate with, for example, eNodeB 160. In an aspect, forexample, modem 108 can configure transceiver 106 to operate at aspecified frequency and power level based on the UE configuration of theUE 110 and communication protocol used by modem 108.

In an aspect, modem 108 can be a multiband-multimode modem, which canprocess digital data and communicate with transceiver 106 such that thedigital data is sent and received using transceiver 106. In an aspect,modem 108 can be multiband and be configured to support multiplefrequency bands for a specific communications protocol. In an aspect,modem 108 can be multimode and be configured to support multipleoperating networks and communications protocols. In an aspect, modem 108can control one or more components of UE 110 (e.g., RF front end 104,transceiver 106) to enable transmission and/or reception of signals fromthe network based on a specified modem configuration. In an aspect, themodem configuration can be based on the mode of the modem and thefrequency band in use. In another aspect, the modem configuration can bebased on UE configuration information associated with UE 110 as providedby the network during cell selection and/or cell reselection.

UE 110 may further include a memory 105, such as for storing data usedherein and/or local versions of applications or uplink scheduler 120and/or one or more of its subcomponents being executed by processor 103.Memory 105 can include any type of computer-readable medium usable by acomputer or processor 103, such as random access memory (RAM), read onlymemory (ROM), tapes, magnetic discs, optical discs, volatile memory,non-volatile memory, and any combination thereof In an aspect, forexample, memory 105 may be a computer-readable storage medium thatstores one or more computer-executable codes defining uplink scheduler120 and/or one or more of its subcomponents, and/or data associatedtherewith, when UE 110 is operating processor 103 to execute uplinkscheduler 120 and/or one or more of its subcomponents. In anotheraspect, for example, memory 105 may be a non-transitorycomputer-readable storage medium.

The eNodeB 160 may include a scheduler 170 having hardware, firmware,and/or software code executable by a processor (e.g. processor(s)183)for scheduling uplink transmissions from one or more UEs 110, thecode comprising instructions and being stored in a memory (e.g., memory185 or another computer-readable medium). In an aspect, the scheduler170 may be implemented by a processor 183 and memory 185. The scheduler170 may communicate via a transceiver 186 and RF front end 184, whichmay be similar to the transceiver 106 and RF front end 104,respectively. The scheduler 170 may determine when each UE 110 isallowed to transmit in the uplink. The scheduler 170 may allocateresources to the UE 110 to use for the uplink transmission 152. Thescheduler 170 may generate uplink scheduling grants 150 to indicate ascheduling of uplink transmission to the UE 110. In an aspect, thescheduler 170 may update a scheduled uplink grant for a UE 110. Forexample, after the eNodeB 160 has transmitted a first grant 150 for anuplink sub-frame, the scheduler 170 may receive additional informationsuch as updated channel quality information, decoding status for a HARQprocess, additional scheduling information, or other information thatmay affect uplink transmissions. The scheduler 170 may update thescheduled uplink transmissions based on the additional information andsend a new or subsequent grant 150 for the same uplink sub-frame. In anaspect, the scheduler 170 may generate joint grants which allocateresources for multiple uplink sub-frames and individual grants whichallocate resources for single sub-frames. The scheduler 170 may includea transmitting component 172, a receiving component 174, and a decodingcomponent 176

The transmitting component 172 may include hardware, firmware, and/orsoftware code executable by a processor for transmitting one or moreuplink scheduling grants 150 for at least a first uplink sub-frame, thecode comprising instructions and being stored in a memory (e.g.,computer-readable medium). For example, the transmitting component 172may include a transmit processor (e.g., TX MIMO Processor 1120 (FIG.11)) and a transmitter (e.g., transmitter 1122 (FIG. 11). Thetransmitting component 172 may format the uplink scheduling grant 150based on a radio frame structure. In an aspect, multiple radio framestructures may use the same format for grants to minimize complexity ofthe format and reduce blind detection of the grants. For example, theformat may define information elements for each uplink sub-frame in theradio frame structure. In an aspect, the format may be based on aworst-case scenario where the format is long enough for each sub-framein a valid radio frame structure having the most uplink sub-frames. Inanother aspect, a small number of formats may be used for different setsof radio frame structures. For example, one format may be used for radioframes having three of fewer uplink sub-frames and a second format maybe used for radio frames having more uplink sub-frames.

The receiving component 174 may include hardware, firmware, and/orsoftware code executable by a processor (e.g., processor(s) 183)forreceiving, in an uplink sub-frame, an uplink transmission from the UE110, the code comprising instructions and being stored in a memory(e.g., memory 185 or another computer-readable medium). For example, thereceiving component 174 may include or control an antenna (e.g., antenna182), and a receiver. In an aspect, the transmitting component 172 andthe receiving component 174 may share a transceiver (e.g., transceiver186) and/or receive/transmit chain components (e.g., an RF front end 184and antenna 182).

The decoding component 176 may include hardware, firmware, and/orsoftware code executable by a processor for decoding a receivedtransmission, the code comprising instructions and being stored in amemory (e.g., computer-readable medium). For example, the decodingcomponent 176 may include a receive processor and/or a modem. In anaspect, the decoding component 176 may decode a received transmissionbased on a transmitted uplink scheduling grant. The decoding component176 may use the transmitted uplink scheduling grant to determine theresources, MCS, waveform, etc. used by the UE 110 for the uplinktransmission 152. In an aspect, the uplink transmission 152 may includean indication of an uplink scheduling grant used by the UE 110. Forexample, a one bit flag may be punctured in one or more resourceelements to indicate a grant. As another example, a differentdemodulation reference signal (DM-RS) cyclic shift may indicate anuplink scheduling grant used for the uplink transmission. In an aspect,the decoding component 176 may also be capable of blind detection todetermine an uplink scheduling grant used by the UE 110.

FIG. 2 is a block diagram conceptually illustrating an example of aframe structure in a telecommunications system in accordance with anaspect of the present disclosure. The transmission timeline for thedownlink may be partitioned into units of radio frames 202, 204, 206.Each radio frame 202, 204, 206 may have a predetermined duration (e.g.,10 milliseconds (ms), 4 ms, or 2 ms) and may be partitioned into, e.g.,10 sub-frames 210 with indices of 0 through 9. Each sub-frame 210 may bedesignated as one of a downlink sub-frame (D), uplink sub-frame (U), orspecial sub-frame (S). In an aspect, the first sub-frame 212, with index0, may be a downlink sub-frame. A special sub-frame 214, for examplewith index 5, may separate downlink sub-frames from uplink sub-frames.The configuration of downlink, special, and uplink sub-frames may changeeach radio frame 202, 204, 206. For example, as illustrated, the indices0-4 are downlink sub-frames, index 5 is a special sub-frame indicating achange of direction, indices 6-8 are uplink sub-frames, and index 9 is aspecial sub-frame indicating the end of the frame. In another example,the index 0 may be the only downlink sub-frame, index 1 may be a specialsub-frame, and indices 3-8 may be uplink sub-frames. It should beunderstood that other combinations of downlink, special, and uplinksub-frames may define a frame structure. In an aspect, a communicationsystem 100 may define a set of valid frame structures and provideidentifiers for each valid frame structure that may be used forsignaling the frame structure in use.

The special sub-frame 214 may include a downlink pilot transmission slot(DwPTS), a guard period (GP), and an uplink pilot transmission slot(UpPTS). The DwPTS may carry pilot signals as well as other informationabout the eNodeB 160 (FIG. 1). The UpPTS may carry an uplink pilotsignal as well as other signaling information, such as, for example,selected uplink scheduling grants. In an aspect, the channel assessingcomponent 129 may determine whether an uplink channel or carrier isavailable during the special sub-frame 214. If the channel or carrier isclear, the UE 110 may transmit in each continuous subsequent uplinksub-frame, for example, sub-frames with indices 6, 7, and 8. If,however, the UE 110 does not have an uplink scheduling grant for asub-frame such as index 7, the channel assessing component 129 may needto perform CCA again during the sub-frame with no uplink transmission.In an aspect, if the CCA process cannot be completed, for examplebecause another device is using the channel (e.g., the UE 110 detectsenergy in the channel from another device), the UE 110 may be unable totransmit the scheduled uplink transmission.

As discussed above, the scheduler 170 may transmit the uplink schedulinggrant 150 to the UE 110, and the uplink scheduler 120 may scheduleuplink transmissions based on the received grant. As an example, a grant220 may be received in the sub-frame 212 having index 0. In an aspect, agrant 220 may also be received in a previous radio frame 202. The grant220 may be a joint grant applicable to multiple sub-frames, for example,sub-frames with indices 6-8. The grant 220 may indicate the range ofconsecutive applicable sub-frames by the start and end values, or mayuse a bit-map to indicate applicable uplink sub-frames. The grant 220may further include a HARQ process identifier, for example, 3. The grant220 may further include resource elements to use for an uplinktransmission in each sub-frame. In an aspect, the length of the grant220 may depend on the number of sub-frames indicated. In an aspect, oneor more grant formats may be defined. The format for the grant 220 maybe based on the number of uplink sub-frames in the frame structure. Inanother aspect, the format of the grant may be fixed to handle the worstcase scenario having the maximum number of uplink sub-frames in a validframe structure. The uplink scheduler 120 may determine that the HARQprocess identifier included in the grant 220 is applicable to thesub-frame with index 6. The uplink scheduler 120 may increment the HARQprocess identifier to determine, for example, that sub-frame index 7 isassigned HARQ process 4, and sub-frame index 8 is assigned HARQ process5. The uplink scheduler 120 may use a modulus operation based on thenumber of HARQ processes.

As another example, the UE 110 may receive a second grant 230 insub-frame index 3. The grant 230 may be an individual grant indicatingsub-frame index 8. The grant 230 may further indicate a HARQ process 2,for example, because transmission of HARQ process 2 previously failedand needs to be retransmitted, or HARQ process 2 otherwise includeshigher priority data. The grant 230 may also include different resourcesor a different MCS than the grant 220. The uplink scheduler 120 mayselect the grant 230 for a transmission in uplink sub-frame index 8because the grant 230 was received after the grant 220, in other words,the grant 230 is a more recent grant than the grant 220. In an aspect,the grant 230 may also be a joint grant, in which case the uplinkscheduler 120 may select the grant 230 for multiple uplinktransmissions. In an aspect, the grant 230 may be received a minimumnumber of sub-frames (e.g., 4 sub-frames) before the uplink sub-frameindex 8. If the grant 230 were for an earlier sub-frame that does notmeet the minimum number, for example, sub-frame index 6, the uplinkscheduler 120 may ignore the grant 230 and/or select the earlier grant220.

As another example, a UE may be required to monitor two or more uplinkscheduling grants in one DL sub-frame. In this case, the two or moreuplink scheduling grants may schedule a different set of uplinksub-frames. As an example, a first grant may schedule sub-frames indices6 and 7, while a second grant may schedule sub-frames indices 8 and 9.As another example, two uplink scheduling grants may be received insub-frame index 0. The first uplink scheduling grant schedulessub-frames indices 6, 7 and 8, while the second uplink scheduling grantschedules sub-frame index 9.

FIG. 3 is a block diagram 300 conceptually illustrating examples oftransmission scheduling. As illustrated, four different UEs 310, 320,330, 340 may be scheduled during a frame. Each UE may receive one ormore uplink scheduling grants indicating which uplink sub-frames to usefor transmissions. The frame structure may include three downlink framesin sub-frame indices 0-2, a special sub-frame at index 3, five uplinksub-frames in sub-frame indices 4-8, and a special sub-frame at index 9.

The UE 310 may be scheduled for uplink transmissions during sub-frameindices 4, 5, 7, and 8. The UE 310 may perform an ECCA or CCA procedureduring the special sub-frame at index 3. Accordingly, the ECCA or CCAprocedure may be performed prior to an uplink transmission in sub-frameindex 4. The UE 310 may send uplink transmissions in sub-frame indices 4and 5. At sub-frame index 6, because the UE 310 does not send an uplinktransmission, the UE 310 may perform a second ECCA or CCA procedure toensure the channel is free for transmission in sub-frame indices 7 and8. In other words, because the sub-frame index 6, which immediatelyprecedes sub-frame index 7, does not include an uplink transmission, theUE 310 may perform ECCA or CCA in sub-frame index 6 prior to the uplinktransmission in sub-frame index 7. Accordingly, a first ECCA or CCAprocedure may be performed for sub-frame indices 4 and 5 and a secondECCA or CCA procedure may be performed for subsequent sub-frame indices7 and 8 within the same frame.

The UE 320 may be scheduled for uplink transmissions during sub-frameindices 4-8. The UE 320 may perform an ECCA or CCA procedure during thespecial sub-frame at index 3. The UE 320 may then transmit inconsecutive sub-frame indices 4-8 without performing another ECCA or CCAprocedure.

UE 330 may be scheduled for uplink transmissions during sub-frameindices 4 and 5. The UE 330 may perform an ECCA or CCA procedure duringthe special sub-frame at index 3. The UE 330 may then transmit inconsecutive sub-frame indices 4 and 5 without performing another ECCA orCCA procedure. The UE 330 may power down a transmitter in sub-frameindices 6-8.

UE 340 may be scheduled for uplink transmissions during sub-frameindices 7 and 8. The UE 340 may wait until sub-frame index 6 to performan ECCA or CCA procedure. The UE 340 may then transmit in consecutivesub-frame indices 7 and 8 without performing another ECCA or CCAprocedure.

The scheduling illustrated in FIG. 3 may allow an eNodeB 160 to schedulemultiple UEs during the time period covered by a radio frame. The eNodeBmay assign different uplink sub-frames to each UE. When multiple UEs arescheduled to transmit during the same uplink sub-frame, the eNodeB 160may assign different resource elements to each UE. Such flexibleassignment provides good load balancing in different sub-frames, whichcan be flexibly managed by eNodeB 160. From the perspective a UE, anECCA or CCA procedure may have to be performed one or more times duringthe duration of uplink sub-frames of a frame.

FIG. 4 is a block diagram 400 illustrating a frame 410 having a framestructure including one downlink sub-frame. For example, as illustratedin FIG. 4, the frame 410 may have a single downlink sub-frame at index0. Accordingly, a UE 110 may only receive uplink scheduling grants inthe single sub-frame. One or more grants 420 may be transmitted in thesingle downlink sub-frame to enable uplink scheduling for sub-frameindices 2-8 (and possibly sub-frame index 9, if it also allows uplinktraffic using a portion of the sub-frame). In an aspect, a UE 110 maynot support same-frame uplink scheduling under a minimum number ofsub-frames. For example, a UE 110 may require a 4 ms or 4 sub-framedelay. Accordingly, for sub-frames that do not meet the minimum delay(e.g. sub-frame indices 2 and 3, the UE 110 may not send an uplinktransmission. Alternatively, the UE 110 may use a previously receivedgrant 430 (e.g., from a previous frame) for the uplink sub-frames thatdo not meet the minimum delay.

FIG. 5 is a block diagram 500 illustrating a frame 510 having a framestructure including two downlink sub-frames. For example, as illustratedin FIG. 5, the frame 510 may have a two downlink sub-frames at indices 0and 1. The UE 110 may require, for example, a minimum delay of 3 ms.Accordingly, a first grant 520 received at sub-frame index 0 may be forsub-frame indices 3-9. A second grant 530 may be for sub-frame indices4-9. In an aspect, an uplink scheduling grant may schedule an uplinktransmission during the second special sub-frame at index 9. Sub-frameindices 4-9 may have multiple applicable grants. The UE 110 maydetermine, for each sub-frame, which of the multiple applicable grantsto use for the uplink transmission.

FIG. 6 is a flow diagram illustrating an example method 600 oftransmitting scheduled uplink wireless transmissions. The method 600 maybe performed by a UE 110.

At block 610, the method 600 may include monitoring at least twodownlink sub-frames for scheduling grants. In an aspect, for example,the downlink monitoring component 122 may monitor the at least twodownlink sub-frames for scheduling grants. In an aspect, a firstdownlink sub-frame may be in a first frame and the second downlinksub-frame may be in a second frame that includes an uplink time-slot forthe uplink transmission. The downlink monitoring component 122 maymonitor one or more carriers for scheduling grants. For example, thedownlink monitoring component 122 may monitor for scheduling grants froma first eNodeB 160 on a first carrier and monitor for grants from asecond eNodeB (not shown) on a second carrier.

At block 620, the method 600 may include receiving a first uplinkscheduling grant for at least a first uplink sub-frame. In an aspect,for example, the grant receiving component 124 may receive the firstuplink scheduling grant in one of the at least two downlink sub-framesfor at least a first uplink sub-frame. The first uplink scheduling grantmay be received in a first sub-frame, which may be in a frame prior tothe first uplink-sub frame, or the same frame as the first uplinksub-frame. In an aspect, first uplink scheduling grant may be for anumber of sub-frames based on a frame structure defining whichsub-frames of a radio frame are available for uplink transmissions.Further, the first uplink scheduling grant may indicate a hybridacknowledgement repeat request (HARQ) process identifier for the uplinktransmission in the first uplink sub-frame. The grant receivingcomponent 124 may further assign a second HARQ process identifier to asecond uplink transmission for a second uplink sub-frame indicated bythe first uplink scheduling grant based on the HARQ process identifierfor the first uplink transmission. For example, the grant receivingcomponent 124 may increment the received HARQ process identifier, orotherwise determine a next HARQ process identifier. In an aspect, forexample, the HARQ process ID (e.g., k) for the first uplink sub-framemay be included in the grant 150. The HARQ process ID for eachadditional uplink sub-frame may be (k+i) mod (N), where N is the numberof available HARQ processes and i is the incremental number of eachuplink sub-frame associated with the grant 150. In another aspect, thefirst uplink scheduling grant may indicate a waveform for the uplinktransmission. For example, the uplink scheduling grant may indicatewhether OFDM or SC-FDM should be used for the uplink transmission. Suchindication may be explicit (e.g., 1-bit information field), or implicit.As an example, a higher MCS may be determined to be OFDM while a lowerMCS is associated with SC-FDM. As another example, a rank 1 transmissionmay be associated with SC-FDM while a MIMO transmission may beassociated with OFDM.

At block 630, the method 600 may include receiving a second uplinkscheduling grant in another of the at least two downlink sub-frames forat least the first uplink sub-frame. In an aspect, for example, thegrant receiving component 124 may also receive the second uplinkscheduling grant for at least the first uplink sub-frame. The seconduplink scheduling grant may be of a same size or a different size thanthe first uplink scheduling grant. The set of sub-frames to monitor forthe second uplink scheduling grant may be the same as or different thanthe set of sub-frames to monitor the first uplink scheduling grant. Thesecond uplink scheduling grant may be received in a second downlinksub-frame, which may be subsequent to the first downlink sub-frame. Thesecond downlink sub-frame may be in the same frame as the first uplinksub-frame. In an aspect, the second downlink sub-frame may be a minimumnumber of sub-frames before the first uplink sub-frame. The minimumnumber of sub-frames may be based on a time to receive and process ascheduling grant, for example 4, 3, 2, or 1 sub-frame, depending on theprocessing capabilities of the UE 110. In an aspect, the second uplinkscheduling grant may be received on a carrier that is different than acarrier on which the first uplink scheduling grant was received. As anexample, the second uplink scheduling grant may come from anotherunlicensed carrier or a licensed carrier.

At block 640, the method 600 may include selecting one or both of thefirst uplink scheduling grant and the second uplink scheduling grant foran uplink transmission in the first uplink sub-frame. In an aspect, forexample, the grant selecting component 126 may select one of the firstuplink scheduling grant and the second uplink scheduling grant for anuplink transmission in the first uplink sub-frame. In an aspect,selecting one of the first uplink scheduling grant and the second uplinkscheduling grant may include selecting a most recent uplink schedulinggrant of the first uplink scheduling grant and the second uplinkscheduling grant. In another aspect, selecting one of the first uplinkscheduling grant and the second uplink scheduling grant includesselecting an uplink scheduling grant received in a downlink sub-frame atleast a minimum number of sub-frames before the first uplink sub-frame.

In block 650, the method 600 may optionally include performing a clearchannel assessment before the uplink transmission when no uplinktransmission is scheduled in a sub-frame immediately before the firstuplink sub-frame. In an aspect, for example, the channel assessingcomponent 129 may perform the clear channel assessment before the uplinktransmission when no uplink transmission is scheduled in a sub-frameimmediately before the first uplink sub-frame.

In block 660, the method 600 may include performing an uplinktransmission in the first uplink sub-frame based on one or both of thefirst uplink scheduling grant and the second uplink scheduling grant. Inan aspect, for example, the transmitting component 128 may performingthe uplink transmission in the first uplink sub-frame based on one orboth of the first uplink scheduling grant and the second uplinkscheduling grant. For example, the transmitting component 128 maygenerate a transport block from data in an uplink transmission bufferbased on the one or more selected uplink scheduling grants. Thetransmitting component 128 may encode the data based on a selectedmodulation and coding scheme and a selected waveform. The codedtransport block may then be transmitted via an RF transmitter. In anaspect, the uplink transmission may include an indication of the one ormore uplink scheduling grants selected.

FIG. 7 is a flow diagram illustrating an example method 700 oftransmitting scheduled uplink wireless transmissions. The method 700 maybe performed by a UE 110 or an eNodeB 160.

At block 710, the method 700 may include identifying a frame structure,where the frame structure includes at least two or more sub-frames for asame transmission direction. In an aspect, for example, the uplinkscheduler 120 may identify a frame structure, where the frame structureincludes at least two or more sub-frames for a same transmissiondirection. The transmission direction may be at least one of a downlinkor uplink. Note that if a special sub-frame contains a downlink portionwhich supports downlink control and/or data transmissions, the specialsub-frame can be considered as a sub-frame for a downlink transmissiondirection. Similarly, if a special sub-frame contains an uplink portionwhich supports uplink control or data transmissions, the specialsub-frame can be considered as a sub-frame for an uplink transmissiondirection. In an aspect, there may at least one sub-frame in between afirst set of sub-frames and the second set of sub-frames. For example,the first set of sub-frames may be a set of uplink sub-frames, followedby a special sub-frame, and the second set of sub-frames may be a secondset of uplink sub-frames. In an aspect, no uplink transmission may bescheduled in a sub-frame immediately preceding the first uplinksub-frame in the first set of sub-frames (e.g., because the sub-frameimmediately preceding the first uplink sub-frame is a downlinksub-frame).

At block 720, the method 700 may include performing a first clearchannel assessment prior to transmitting in a first set of sub-frames ofthe at least two or more sub-frames. In an aspect, for example, thechannel assessing component 129 may perform a first clear channelassessment prior to transmitting in a first set of sub-frames of the atleast two or more sub-frames. The first set of sub-frames may, forexample, include consecutive sub-frames in the uplink direction. Theclear channel assessment may at least one of a normal clear channelassessment (CCA) or an extended clear channel assessment (ECCA).

At block 730, the method 700 may include transmitting in the first setof sub-frames based on the first clear channel assessment. In an aspect,for example, the transmitting component 128 may transmit in the firstset of sub-frames based on the first clear channel assessment. Note thatthe actual transmission duration in the first set of sub-frames may beequal to or less than the duration of the first set of sub-frames,depending on the first clear channel assessment. As an example, if thefirst clear channel assessment is cleared at the beginning of the firstset of sub-frames, the transmission may occur during the entire durationof the first set of sub-frames. As another example, if the first clearchannel assessment is cleared at beginning of a second sub-frame of thefirst set of sub-frames, the transmission may occur from the beginningof the second sub-frame to the last sub-frame of the first set ofsub-frames. The transmission in the first set of sub-frames may befurther based on at least one scheduling grant.

At block 740, the method 700 may include determining whether to performa second clear channel assessment prior to transmitting in a second setof sub-frames of the at least two or more sub-frames, where the secondset of sub-frames are subsequent to the first set of sub-frames in theframe. In an aspect, for example, the channel assessing component 129may determine whether to perform a second clear channel assessment priorto transmitting in the second set of sub-frames of the at least two ormore sub-frames, where the second set of sub-frames are subsequent tothe first set of sub-frames in the frame. In an aspect, thedetermination of whether to perform a second clear channel assessmentmay based on the frame structure. For example, the channel assessingcomponent 129 may perform a second channel assessment when the framestructure does not include a transmission in a sub-frame immediatelypreceding the second set of sub-frames. As another example, the channelassessing component 129 may perform a second channel assessment whenthere is at least one sub-frame for a different direction between thefirst set of sub-frames and the second set of sub-frames. In anotheraspect, the determination of whether to perform a second clear channelassessment is based on at least one uplink scheduling grant. Forexample, the channel assessing component 129 may perform a secondchannel assessment when another UE is scheduled to transmit between thefirst set of sub-frames and the second set of sub-frames.

In block 750, the method 700 may include transmitting in the second setof sub-frames based on the second channel assessment. In an aspect, forexample, the transmitting component 128 may transmit in the second setof sub-frames based on the second channel assessment. The transmissionin the second set of sub-frames may be further based on at least oneuplink scheduling grant. The uplink scheduling grant for the second setof sub-frames may be the same as or different from the uplink schedulinggrant corresponding to the first set of sub-frames.

FIG. 8 is a flow diagram illustrating an example method 800 ofscheduling uplink wireless transmissions. The method 800 may beperformed by an eNodeB 160.

In block 810, the method 800 may include transmitting, to a device, afirst uplink scheduling grant for at least a first uplink sub-frame. Inan aspect, for example, the transmitting component 172 may transmit thefirst uplink scheduling grant for at least a first uplink sub-frame. Inan aspect, the device may be the UE 110.

In block 815, the method 800 may optionally include receiving updatedcondition information. In an aspect, for example, the receivingcomponent 174 may receive the updated condition information. In anotheraspect, the updated condition information may be received via a networkinterface from a network node such as another eNodeB or a servinggateway.

In block 820, the method 800 may include transmitting, to the device, asecond uplink scheduling grant for at least the first uplink sub-frame.In an aspect, for example, the transmitting component 172 may alsotransmit, to the UE 110, the second uplink scheduling grant for at leastthe first uplink sub-frame. In an aspect, the second uplink schedulinggrant may indicate a HARQ process identifier for the uplinktransmission. The second uplink scheduling grant may also indicate awaveform for the uplink transmission. In an aspect, the first uplinkscheduling grant may be transmitted in a first frame and the seconduplink scheduling grant may be transmitted in a second frame thatincludes the first uplink sub-frame. The second uplink scheduling grantmay be transmitted at least a minimum number of sub-frames before theuplink transmission.

In block 830, the method 800 may include receiving, in the first uplinksub-frame, an uplink transmission from the device. In an aspect, forexample, the receiving component 174 may receive, in the first uplinksub-frame, the uplink transmission from the device, which may be the UE110. In an aspect, the uplink transmission may include an indication ofan uplink scheduling grant selected by the device.

In block 840, the method 800 may include processing the uplinktransmission according to one of the first uplink scheduling grant andthe second uplink scheduling grant. In an aspect, for example, thedecoding component 176 may process the uplink transmission according toone of the first uplink scheduling grant and the second uplinkscheduling grant. If the uplink transmission includes an indication ofan uplink scheduling grant selected by the device, the decodingcomponent 176 may process the uplink transmission according to theselected uplink scheduling grant.

FIG. 9 illustrates several sample components (represented bycorresponding blocks) that may be incorporated into an apparatus 902 andan apparatus 904(e.g., corresponding to a UE 110 and an eNodeB 160,respectively) to support uplink scheduling operations as taught herein.The apparatus 902 and the apparatus 904, for example, may include anuplink scheduler 120 and scheduler 170, respectively, for schedulinguplink transmissions of UE 110. It should be appreciated that thesecomponents may be implemented in different types of apparatuses indifferent implementations (e.g., in an ASIC, in an SoC, etc.). Thedescribed components also may be incorporated into other apparatuses ina communication system. For example, other apparatuses in a system mayinclude components similar to those described to provide similarfunctionality. Also, a given apparatus may contain one or more of thedescribed components. For example, an apparatus may include multipletransceiver components that enable the apparatus to operate on multiplecarriers and/or communicate via different technologies.

The apparatus 902 and the apparatus 904 each include at least onewireless communication device (represented by the communication devices908 and 914 (and the communication device 920 if the apparatus 904 is arelay)) for communicating with other nodes via at least one designatedradio access technology. Each communication device 908 includes at leastone transmitter (represented by the transmitter 910) for transmittingand encoding signals (e.g., messages, indications, information, and soon) and at least one receiver (represented by the receiver 912) forreceiving and decoding signals (e.g., messages, indications,information, pilots, and so on). Similarly, each communication device914 includes at least one transmitter (represented by the transmitter916) for transmitting signals (e.g., messages, indications, information,pilots, and so on) and at least one receiver (represented by thereceiver 918) for receiving signals (e.g., messages, indications,information, and so on). If the apparatus 904 is a relay access point,each communication device 920 may include at least one transmitter(represented by the transmitter 922) for transmitting signals (e.g.,messages, indications, information, pilots, and so on) and at least onereceiver (represented by the receiver 924) for receiving signals (e.g.,messages, indications, information, and so on).

A transmitter and a receiver may comprise an integrated device (e.g.,embodied as a transmitter circuit and a receiver circuit of a singlecommunication device) in some implementations, may comprise a separatetransmitter device and a separate receiver device in someimplementations, or may be embodied in other ways in otherimplementations. In some aspects, a wireless communication device (e.g.,one of multiple wireless communication devices) of the apparatus 904comprises a network listen module.

The apparatuses 902, 904, also include other components that may be usedin conjunction with uplink scheduling operations as taught herein. Theapparatus 902 includes a processing system 932 for providingfunctionality relating to, for example, communicating with an eNodeB tosupport uplink scheduling as taught herein and for providing otherprocessing functionality. The apparatus 904 includes a processing system934 for providing functionality relating to, for example, uplinkscheduling as taught herein and for providing other processingfunctionality. The apparatuses 902, and 904, include memory devices 938,and 940 (e.g., each including a memory device), respectively, formaintaining information (e.g., information indicative of reservedresources, thresholds, parameters, and so on). In addition, theapparatuses 902, 904, and 906 include user interface devices 944 and 948respectively, for providing indications (e.g., audible and/or visualindications) to a user and/or for receiving user input (e.g., upon useractuation of a sensing device such a keypad, a touch screen, amicrophone, and so on).

For convenience, the apparatus 902 is shown in FIG. 9 as includingcomponents that may be used in the various examples described herein. Inpractice, the illustrated blocks may have different functionality indifferent aspects.

The components of FIG. 9 may be implemented in various ways. In someimplementations, the components of FIG. 9 may be implemented in one ormore circuits such as, for example, one or more processors and/or one ormore ASICs (which may include one or more processors). Here, eachcircuit may use and/or incorporate at least one memory component forstoring information or executable code used by the circuit to providethis functionality. For example, some or all of the functionalityrepresented by blocks 908, 932, 938, and 944 may be implemented byprocessor and memory component(s) of the apparatus 902 (e.g., byexecution of appropriate code and/or by appropriate configuration ofprocessor components). Similarly, some or all of the functionalityrepresented by blocks 914, 920, 934, 940, and 946 may be implemented byprocessor and memory component(s) of the apparatus 904 (e.g., byexecution of appropriate code and/or by appropriate configuration ofprocessor components).

Some of the eNodeBs referred to herein may comprise low-power eNodeBs orlow power access points. In a typical network, low-power access points(e.g., femto cells) are deployed to supplement conventional networkaccess points (e.g., macro access points). For example, a low-poweraccess point installed in a user's home or in an enterprise environment(e.g., commercial buildings) may provide voice and high speed dataservice for access terminals supporting cellular radio communication(e.g., CDMA, WCDMA, UMTS, LTE, etc.). In general, these low-power accesspoints provide more robust coverage and higher throughput for accessterminals in the vicinity of the low-power access points.

As used herein, the term low-power access point refers to an accesspoint having a transmit power (e.g., one or more of: maximum transmitpower, instantaneous transmit power, nominal transmit power, averagetransmit power, or some other form of transmit power) that is less thana transmit power (e.g., as defined above) of any macro access point inthe coverage area. In some implementations, each low-power access pointhas a transmit power (e.g., as defined above) that is less than atransmit power (e.g., as defined above) of the macro access point by arelative margin (e.g., 10 dBm or more). In some implementations,low-power access points such as femto cells may have a maximum transmitpower of 20 dBm or less. In some implementations, low-power accesspoints such as pico cells may have a maximum transmit power of 24 dBm orless. It should be appreciated, however, that these or other types oflow-power access points may have a higher or lower maximum transmitpower in other implementations (e.g., up to 1 Watt in some cases, up to10 Watts in some cases, and so on).

Typically, low-power access points connect to the Internet via abroadband connection (e.g., a digital subscriber line (DSL) router, acable modem, or some other type of modem) that provides a backhaul linkto a mobile operator's network. Thus, a low-power access point deployedin a user's home or business provides mobile network access to one ormore devices via the broadband connection.

Various types of low-power access points may be employed in a givensystem. For example, low-power access points may be implemented as orreferred to as femto cells, femto access points, small cells, femtonodes, home NodeBs (HNBs), home eNodeBs (HeNBs), access point basestations, pico cells, pico nodes, or micro cells.

For convenience, low-power access points may be referred to simply assmall cells in the discussion that follows. Thus, it should beappreciated that any discussion related to small cells herein may beequally applicable to low-power access points in general (e.g., to femtocells, to micro cells, to pico cells, etc.).

Small cells may be configured to support different types of accessmodes. For example, in an open access mode, a small cell may allow anyaccess terminal to obtain any type of service via the small cell. In arestricted (or closed) access mode, a small cell may only allowauthorized access terminals to obtain service via the small cell. Forexample, a small cell may only allow access terminals (e.g., so calledhome access terminals) belonging to a certain subscriber group (e.g., aclosed subscriber group (CSG)) to obtain service via the small cell. Ina hybrid access mode, alien access terminals (e.g., non-home accessterminals, non-CSG access terminals) may be given limited access to thesmall cell. For example, a macro access terminal that does not belong toa small cell's CSG may be allowed to access the small cell only ifsufficient resources are available for all home access terminalscurrently being served by the small cell.

Thus, small cells operating in one or more of these access modes may beused to provide indoor coverage and/or extended outdoor coverage. Byallowing access to users through adoption of a desired access mode ofoperation, small cells may provide improved service within the coveragearea and potentially extend the service coverage area for users of amacro network.

Thus, in some aspects the teachings herein may be employed in a networkthat includes macro scale coverage (e.g., a large area cellular networksuch as a third generation (3G) network, typically referred to as amacro cell network or a WAN) and smaller scale coverage (e.g., aresidence-based or building-based network environment, typicallyreferred to as a LAN). As an access terminal (AT) moves through such anetwork, the access terminal may be served in certain locations byaccess points that provide macro coverage while the access terminal maybe served at other locations by access points that provide smaller scalecoverage. In some aspects, the smaller coverage nodes may be used toprovide incremental capacity growth, in-building coverage, and differentservices (e.g., for a more robust user experience).

In the description herein, a node (e.g., an access point) that providescoverage over a relatively large area may be referred to as a macroaccess point while a node that provides coverage over a relatively smallarea (e.g., a residence) may be referred to as a small cell. It shouldbe appreciated that the teachings herein may be applicable to nodesassociated with other types of coverage areas. For example, a picoaccess point may provide coverage (e.g., coverage within a commercialbuilding) over an area that is smaller than a macro area and larger thana femto cell area. In various applications, other terminology may beused to reference a macro access point, a small cell, or other accesspoint-type nodes. For example, a macro access point may be configured orreferred to as an access node, base station, access point, eNodeB, macrocell, and so on. In some implementations, a node may be associated with(e.g., referred to as or divided into) one or more cells or sectors. Acell or sector associated with a macro access point, a femto accesspoint, or a pico access point may be referred to as a macro cell, afemto cell, or a pico cell, respectively.

The teachings herein may be employed in a wireless multiple-accesscommunication system that simultaneously supports communication formultiple wireless access terminals. Here, each terminal may communicatewith one or more access points via transmissions on the forward andreverse links. The forward link (or downlink) refers to thecommunication link from the access points to the terminals, and thereverse link (or uplink) refers to the communication link from theterminals to the access points. This communication link may beestablished via a single-in-single-out system, amultiple-in-multiple-out (MIMO) system, or some other type of system.

A MIMO system employs multiple (N_(T)) transmit antennas and multiple(N_(R)) receive antennas for data transmission. A MIMO channel formed bythe N_(T) transmit and N_(R) receive antennas may be decomposed intoN_(S) independent channels, which are also referred to as spatialchannels, where N_(S)≤min {N_(T), N_(R)}. Each of the N_(S) independentchannels corresponds to a dimension. The MIMO system may provideimproved performance (e.g., higher throughput and/or greaterreliability) if the additional dimensionalities created by the multipletransmit and receive antennas are utilized.

A MIMO system may support time division duplex (TDD) and frequencydivision duplex (FDD). In a TDD system, the forward and reverse linktransmissions are on the same frequency region so that the reciprocityprinciple allows the estimation of the forward link channel from thereverse link channel. This enables the access point to extract transmitbeam-forming gain on the forward link when multiple antennas areavailable at the access point.

FIG. 10 illustrates in more detail the components of a wireless device1010 (e.g., an eNodeB 160) and a wireless device 1050 (e.g., a UE 110)of a sample communication system 1000 that may be adapted as describedherein. For example, wireless device 1010 may include a scheduler 170and wireless device 1050 may include an uplink scheduler 120 forscheduling uplink transmissions. The scheduler 170 may be a separatecomponent or may be implemented by components such as TX data processor1014 and TX MIMO processor 1020 of wireless device 1010. The uplinkscheduler 120 may be implemented by TX data processor 1038 of wirelessdevice 1050. At the device 1010, traffic data for a number of datastreams is provided from a data source 1012 to a transmit (TX) dataprocessor 1014. Each data stream may then be transmitted over arespective transmit antenna. The scheduler 170 (FIG. 1) may beimplemented by the TX data processor 1014.

The TX data processor 1014 formats, codes, and interleaves the trafficdata for each data stream based on a particular coding scheme selectedfor that data stream to provide coded data. In an aspect, the trafficdata may include uplink scheduling grants for the wireless device 1050.The coded data for each data stream may be multiplexed with pilot datausing OFDM techniques. The pilot data is typically a known data patternthat is processed in a known manner and may be used at the receiversystem to estimate the channel response. The multiplexed pilot and codeddata for each data stream is then modulated (i.e., symbol mapped) basedon a particular modulation scheme (e.g., BPSK, QSPK, M-PSK, or M-QAM)selected for that data stream to provide modulation symbols. The datarate, coding, and modulation for each data stream may be determined byinstructions performed by a processor 1030. A data memory 1032 may storeprogram code, data, and other information used by the processor 1030 orother components of the device 1010.

The modulation symbols for all data streams are then provided to a TXMIMO processor 1020, which may further process the modulation symbols(e.g., for OFDM). The TX MIMO processor 1020 then provides N_(T)modulation symbol streams to N_(T) transceivers (XCVR) 1022A through1022T. In some aspects, the TX MIMO processor 1020 applies beam-formingweights to the symbols of the data streams and to the antenna from whichthe symbol is being transmitted.

Each transceiver 1022 receives and processes a respective symbol streamto provide one or more analog signals, and further conditions (e.g.,amplifies, filters, and upconverts) the analog signals to provide amodulated signal suitable for transmission over the MIMO channel. N_(T)modulated signals from transceivers 1022A through 1022T are thentransmitted from N_(T) antennas 1024A through 1024T, respectively.

At the wireless device 1050, the transmitted modulated signals arereceived by N_(R) antennas 1052A through 1052R and the received signalfrom each antenna 1052 is provided to a respective transceiver (XCVR)1054A through 1054R. Each transceiver 1054 conditions (e.g., filters,amplifies, and downconverts) a respective received signal, digitizes theconditioned signal to provide samples, and further processes the samplesto provide a corresponding “received” symbol stream.

A receive (RX) data processor 1060 then receives and processes the N_(R)received symbol streams from N_(R) transceivers 1054 based on aparticular receiver processing technique to provide N_(T) “detected”symbol streams. The RX data processor 1060 then demodulates,deinterleaves, and decodes each detected symbol stream to recover thetraffic data for the data stream. In an aspect, the traffic data mayinclude the uplink scheduling grants 150 (FIG. 1). The processing by theRX data processor 1060 is complementary to that performed by the TX MIMOprocessor 1020 and the TX data processor 1014 at the device 1010.

The uplink scheduler 120 may determine, for each sub-frame, whether thereceived uplink scheduling grants 150 allow a transmission and amodulation and coding scheme and waveform to use for the transmission. Aprocessor 1070 periodically determines which pre-coding matrix to use.The processor 1070 formulates a reverse link message comprising a matrixindex portion and a rank value portion. A data memory 1072 may storeprogram code, data, and other information used by the processor 1070 orother components of the wireless device 1050.

The reverse link message may comprise various types of informationregarding the communication link and/or the received data stream. Thereverse link message is then processed by a TX data processor 1038,which also receives traffic data for a number of data streams from adata source 1036, modulated by a modulator 1080, conditioned by thetransceivers 1054A through 1054R based on the uplink scheduling grants150, and transmitted back to the device 1010.

At the device 1010, the modulated signals from the wireless device 1050are received by the antennas 1024, conditioned by the transceivers 1022,demodulated by a demodulator (DEMOD) 1040, and processed by a RX dataprocessor 1042 to extract the reverse link message transmitted by thewireless device 1050. The processor 1030 then determines whichpre-coding matrix to use for determining the beam-forming weights thenprocesses the extracted message.

It will be appreciated that for each wireless device 1010 and 1050 thefunctionality of two or more of the described components may be providedby a single component. It will be also be appreciated that the variouscommunication components illustrated in FIG. 10 and described above maybe further configured as appropriate to perform communication adaptationas taught herein. For example, the processors 1030/1070 may cooperatewith the memories 1032/1072 and/or other components of the respectivedevices 1010/1050 to perform the communication adaptation as taughtherein. In some aspects, an apparatus or any component of an apparatusmay be configured to (or operable to or adapted to) providefunctionality as taught herein. This may be achieved, for example: bymanufacturing (e.g., fabricating) the apparatus or component so that itwill provide the functionality; by programming the apparatus orcomponent so that it will provide the functionality; or through the useof some other suitable implementation technique. As one example, anintegrated circuit may be fabricated to provide the requisitefunctionality. As another example, an integrated circuit may befabricated to support the requisite functionality and then configured(e.g., via programming) to provide the requisite functionality. As yetanother example, a processor circuit may execute code to provide therequisite functionality.

It should be understood that any reference to an element herein using adesignation such as “first,” “second,” and so forth does not generallylimit the quantity or order of those elements. Rather, thesedesignations may be used herein as a convenient method of distinguishingbetween two or more elements or instances of an element. Thus, areference to first and second elements does not mean that only twoelements may be employed there or that the first element must precedethe second element in some manner. Also, unless stated otherwise a setof elements may comprise one or more elements. In addition, terminologyof the form “at least one of A, B, or C” or “one or more of A, B, or C”or “at least one of the group consisting of A, B, and C” used in thedescription or the claims means “A or B or C or any combination of theseelements.” For example, this terminology may include A, or B, or C, or Aand B, or A and C, or A and B and C, or 2A, or 2B, or 2C, and so on.

Those of skill in the art will appreciate that information and signalsmay be represented using any of a variety of different technologies andtechniques. For example, data, instructions, commands, information,signals, bits, symbols, and chips that may be referenced throughout theabove description may be represented by voltages, currents,electromagnetic waves, magnetic fields or particles, optical fields orparticles, or any combination thereof

Further, those of skill in the art will appreciate that the variousillustrative logical blocks, modules, circuits, and algorithm stepsdescribed in connection with the aspects disclosed herein may beimplemented as electronic hardware, computer software, or combinationsof both. To clearly illustrate this interchangeability of hardware andsoftware, various illustrative components, blocks, modules, circuits,and steps have been described above generally in terms of theirfunctionality. Whether such functionality is implemented as hardware orsoftware depends upon the particular application and design constraintsimposed on the overall system. Skilled artisans may implement thedescribed functionality in varying ways for each particular application,but such implementation decisions should not be interpreted as causing adeparture from the scope of the present disclosure.

The methods, sequences and/or algorithms described in connection withthe aspects disclosed herein may be embodied directly in hardware, in asoftware module executed by a processor, or in a combination of the two.A software module may reside in RAM memory, flash memory, ROM memory,EPROM memory, EEPROM memory, registers, hard disk, a removable disk, aCD-ROM, or any other form of storage medium known in the art. Anexemplary storage medium is coupled to the processor such that theprocessor can read information from, and write information to, thestorage medium. In the alternative, the storage medium may be integralto the processor.

Accordingly, an aspect of the disclosure can include a computer readablemedium embodying a method for dynamic bandwidth management fortransmissions in unlicensed spectrum. Accordingly, the disclosure is notlimited to the illustrated examples.

While the foregoing disclosure shows illustrative aspects, it should benoted that various changes and modifications could be made hereinwithout departing from the scope of the disclosure as defined by theappended claims. The functions, steps and/or actions of the methodclaims in accordance with the aspects of the disclosure described hereinneed not be performed in any particular order. Furthermore, althoughcertain aspects may be described or claimed in the singular, the pluralis contemplated unless limitation to the singular is explicitly stated.

What is claimed is:
 1. A method for transmitting scheduled uplink wireless transmissions, the method comprising: monitoring at least two downlink sub-frames for uplink scheduling grants; receiving a first uplink scheduling grant in one of the at least two downlink sub-frames for at least a first uplink sub-frame; receiving a second uplink scheduling grant in another of the at least two downlink sub-frames for at least the first uplink sub-frame, wherein the second downlink subframe is subsequent to the first downlink sub-frame and at least a minimum number of sub-frames before the first uplink sub-frame; and performing an uplink transmission in the first uplink sub-frame based on one or both of the first uplink scheduling grant and the second uplink scheduling grant.
 2. The method of claim 1, wherein the minimum number of subframes is based on a capability of a transmitting device.
 3. The method of claim 1, wherein the minimum number of subframes is
 3. 4. The method of claim 1, wherein the first uplink sub-frame is at least 4 sub-frames after the first uplink scheduling grant.
 5. The method of claim 1, wherein the first uplink scheduling grant is for a number of sub-frames based on a frame structure defining which sub-frames of a radio frame are available for uplink transmissions.
 6. The method of claim 1, wherein the first uplink scheduling grant indicates a hybrid acknowledgement repeat request (HARQ) process identifier for the uplink transmission in the first uplink sub-frame.
 7. The method of claim 6, further comprising assigning a second HARQ process identifier to a second uplink transmission in a second uplink sub-frame based on the HARQ process identifier for the uplink transmission, wherein the first uplink scheduling grant is also for the second uplink sub-frame, and wherein the second uplink sub-frame is subsequent to the first uplink sub-frame.
 8. The method of claim 1, further comprising combining resource allocations from the first uplink scheduling grant and the second uplink scheduling grant.
 9. The method of claim 1, wherein the first uplink scheduling grant indicates a waveform for the uplink transmission.
 10. The method of claim 1, wherein receiving the first uplink scheduling grant comprises receiving the first uplink scheduling grant on a first carrier and receiving the second uplink scheduling grant comprises receiving the second uplink scheduling grant on a second carrier.
 11. The method of claim 1, wherein receiving the first uplink scheduling grant comprises receiving the first uplink scheduling grant in a first frame and receiving the second uplink scheduling grant comprises receiving the second uplink scheduling grant in a subsequent second frame that includes the first uplink sub-frame.
 12. The method of claim 1, wherein the uplink transmission includes an indication of the at least one of the first uplink scheduling grant and the second uplink scheduling grant used for the uplink transmission.
 13. The method of claim 1, further comprising performing a clear channel assessment prior to the uplink transmission in the first uplink sub-frame.
 14. The method of claim 13, further comprising determining whether to perform a second clear channel assessment prior to a second uplink transmission in a second uplink sub-frame, wherein at least one of the first uplink scheduling grant and the second uplink scheduling grant is also for the second uplink sub-frame, and wherein the second uplink sub-frame is subsequent to the first uplink sub-frame within a same frame.
 15. The method of claim 13, further comprising performing an uplink transmission in each of a set of consecutive sub-frames based on the clear channel assessment prior to the uplink transmission in the first uplink sub-frame.
 16. An apparatus for transmitting scheduled uplink wireless transmissions, the apparatus comprising: means for monitoring at least two downlink sub-frames for scheduling grants; means for receiving a first uplink scheduling grant in one of the at least two downlink sub-frames for at least a first uplink sub-frame; means for receiving a second uplink scheduling grant in another of the at least two downlink sub-frames for at least the first uplink sub-frame, wherein the second downlink subframe is subsequent to the first downlink sub-frame and at least a minimum number of sub-frames before the first uplink sub-frame; and means for performing an uplink transmission in the first uplink sub-frame based on one or both of the first uplink scheduling grant and the second uplink scheduling grant.
 17. The apparatus of claim 16, wherein the minimum number of subframes is based on an indicated capability of the apparatus.
 18. The apparatus of claim 16, wherein the minimum number of subframes is
 3. 19. The apparatus of claim 16, wherein the first uplink sub-frame is at least 4 sub-frames after the first uplink scheduling grant.
 20. The apparatus of claim 16, wherein the first uplink scheduling grant indicates a hybrid acknowledgement repeat request (HARQ) process identifier for the uplink transmission.
 21. The apparatus of claim 20, further comprising means for assigning a second HARQ process identifier to a second uplink transmission for a second uplink sub-frame based on the HARQ process identifier for the uplink transmission, wherein the first uplink scheduling grant is also for the second uplink sub-frame, and wherein the second uplink sub-frame is subsequent to the first uplink sub-frame.
 22. The apparatus of claim 16, further comprising means for performing a clear channel assessment prior to the uplink transmission in the first uplink sub-frame.
 23. An apparatus for transmitting scheduled uplink wireless transmissions, the apparatus comprising: a transceiver configured to receive scheduling grants in one or more downlink sub-frames and transmit data in one or more uplink sub-frames; a memory; and a processor communicatively coupled to the transceiver and the memory, the processor and the memory configured to: monitor, via the transceiver, at least two of the one or more downlink sub-frames for the scheduling grants; receive a first uplink scheduling grant in one of the at least two downlink sub-frames for at least a first uplink sub-frame of the one or more uplink sub-frames; receive a second uplink scheduling grant in another of the at least two downlink sub-frames for at least the first uplink sub-frame, wherein the second downlink subframe is subsequent to the first downlink sub-frame and at least a minimum number of sub-frames before the first uplink sub-frame; and perform an uplink transmission in the first uplink sub-frame based on one or both of the first uplink scheduling grant and the second uplink scheduling grant.
 24. The apparatus of claim 23, wherein the minimum number of subframes is based on an indicated a capability of the apparatus.
 25. The apparatus of claim 23, wherein the minimum number of subframes is
 3. 25. The apparatus of claim 23, wherein the first uplink sub-frame is at least 4 sub-frames after the first uplink scheduling grant.
 26. The apparatus of claim 23, wherein the first uplink scheduling grant indicates a hybrid acknowledgement repeat request (HARQ) process identifier for the uplink transmission.
 27. The apparatus of claim 26, wherein the processor and memory are configured to assign a second HARQ process identifier to a second uplink transmission for a second uplink sub-frame based on the HARQ process identifier for the uplink transmission, wherein the first uplink scheduling grant is also for the second uplink sub-frame, and wherein the second uplink sub-frame is subsequent to the first uplink sub-frame.
 28. The apparatus of claim 23, wherein the processor and memory are configured to perform a clear channel assessment prior to the uplink transmission in the first uplink sub-frame.
 29. A computer-readable medium storing computer executable code for transmitting scheduled uplink wireless transmissions, comprising: code for monitoring at least two downlink sub-frames for scheduling grants; code for receiving a first uplink scheduling grant in one of the at least two downlink sub-frames for at least a first uplink sub-frame; code for receiving a second uplink scheduling grant in another of the at least two downlink sub-frames for at least the first uplink sub-frame, wherein the second downlink subframe is subsequent to the first downlink sub-frame and at least a minimum number of sub-frames before the first uplink sub-frame; and code for performing an uplink transmission in the first uplink sub-frame based on one or both of the first uplink scheduling grant and the second uplink scheduling grant.
 30. The computer-readable medium of claim 29, wherein the minimum number of subframes is based on a capability of a transmitting device. 